[FFmpeg-cvslog] Prevent NULL dereference when the huffman table is invalid in the 4xm decoder .

[Laurent Aimar]

ffmpeg | branch: release/0.8 | Laurent Aimar <fenrir at videolan.org> | Sun Oct  2 00:38:28 2011 +0200| [535112b3658c21d1f9c4d2b44689342a32ff6eea] | committer: Michael Niedermayer

Prevent NULL dereference when the huffman table is invalid in the 4xm decoder.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit 4a8ff0636d67c6df059f2ae2df49ad1181de14ca)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=535112b3658c21d1f9c4d2b44689342a32ff6eea
---

 libavcodec/4xm.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c
index d89b494..1ec64ae 100644
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@@ -601,9 +601,10 @@ static const uint8_t *read_huffman_tables(FourXContext *f, const uint8_t * const
         len_tab[j]= len;
     }
 
-    init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257,
-             len_tab , 1, 1,
-             bits_tab, 4, 4, 0);
+    if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257,
+                 len_tab , 1, 1,
+                 bits_tab, 4, 4, 0))
+        return NULL;
 
     return ptr;
 }